Conventionally, as a reference function of words in document data managed by a computer, an online dictionary that can be used by cutting and pasting a character string on a display is known. Also, a word reference function that uses a link function of hypertext or the like is known. Some of these reference functions issue a reference request to a character code or the display position of character information displayed as a two-dimensional image.
In “Speech synthesis apparatus” of Japanese Patent Application Laid-Open No. 10-171485 and “Japanese text reading word edit processing method” of Japanese Patent Application Laid-Open No. 5-22487, text is read aloud after words which are hard for the user to understand, and those which are misleading due to having a multiplicity of meanings, are replaced by other words or meanings in advance.
Also, in “Information acquisition support method and apparatus” of Japanese Patent Application Laid-Open No. 10-134068, speech is output while displaying a document, words in the displayed document are registered as a recognition vocabulary for speech recognition, and the meaning and example of a word uttered by the user are presented.
The above examples of the online dictionary and hypertext are premised on the display of document data, and the user designates a word to be examined using a character code or position information in the document data. For this reason, these examples are not premised on the display of document data that contains words to be referred to, and cannot be used to designate a word on the condition that the user acquires information only by speech.
In the methods of Japanese Patent Application Laid-Open Nos. 10-171485 and 5-22487, in which text is read after words which are hard for the user to understand, and those which are misleading due to having a multiplicity of meanings, are replaced by other words or meanings in advance, original document data is modified. Therefore, such methods are not suitable for document data such as literary works, the originality of which must be appreciated. When words are replaced by plain ones from the start while the user is listening to document data for the purpose of language learning, the original purpose of learning is not achieved.
Furthermore, in the method of Japanese Patent Application Laid-Open No. 10-134068, which recognizes a word uttered by the user as speech, and presents the meaning and example of that word, if the user fails to catch speech, he or she can no longer designate that word.
In addition, in consideration of use that allows a mobile user who wears a headphone to listen to speech such as from a portable audio device, a function of allowing the user to indicate a given portion for which he or she wants some clarification, without always paying attention to the display, is required.